UPDATE: split the webapp in a widget and the app itself

This splits the webapp in:

* IronCalc (the widget to be published on npmjs)
* The frontend for our "service"
* Adds "dummy code" for the backend using sqlite

webapp/app.ironcalc.com/frontend/src/components/util.ts

@@ -0,0 +1,18 @@
+export function base64ToBytes(base64: string): Uint8Array {
+  //   const binString = atob(base64);
+  //   return Uint8Array.from(binString, (m) => m.codePointAt(0));
+
+  return new Uint8Array(
+    atob(base64)
+      .split("")
+      .map((c) => c.charCodeAt(0)),
+  );
+}
+
+export function bytesToBase64(bytes: Uint8Array): string {
+  const binString = Array.from(bytes, (byte) =>
+    String.fromCodePoint(byte),
+  ).join("");
+  // btoa(String.fromCharCode(...bytes));
+  return btoa(binString);
+}